Although some information is available about the daytime alertness of untreated narcoleptic subjects, studies in a laboratory environment, there are no studies which describe the daytime sleep patterns and daytime alertness of treated narcoleptics outside the laboratory setting. Therefore, using 24 hour ambulatory EEG monitors we will determine: 1) If treated narcoleptic subjects are comparable to matched control subjects in terms of daytime alertness, amount of sleep in a 24 hour period, and distribution of sleep across a 24 hour period; 2) If there is an recognizable pattern to the timing and duration of sleep attacks across the day in treated narcoleptic subjects; and 3) If there are particular activities which apparently induce sleep attacks or particular activities which apparently inhibit sleep attacks? Twenty-five treated narcoleptics and 25 matched control subjects will keep a detailed sleep diary while undergoing 24 hour ambulatory EEG monitoring. In addition, to comparing the timing and duration of sleep in narcoleptic and control groups, recordings from the narcoleptic subjects will be analyzed to determine whether sleep attacks occur at predictable intervals or are more likely to occur in certain circumstances. Frequent, regularly scheduled naps and regular hours for nocturnal sleep are often prescribed to decrease the frequency of sleep attacks and limit the use of stimulants. Even though these prescriptions often require substantial alterations in the patient's lifestyle, little effort has been devoted to systematic testing of various sleep schedules. Therefore, the second major goal of this study is to test the effectiveness of scheduled naps and other sleep schedules in reducing the excessive daytime sleepiness experienced by narcoleptic patients. Eighty treated narcoleptic subjects will keep a sleep diary one week prior to testing, complete the Narcolepsy Symptom Status Checklist (NSSC), and undergo 24 hours of ambulatory EEG monitoring. After completing these preliminary studies, subjects will be randomly assigned to one of four treatment groups: 1) nap therapy group, 2) regular bedtime group, 3) combination group, and 4) control group. Subjects assigned to the nap group will take two brief, scheduled naps per day for three weeks. The subjects assigned to the regular bedtime group will select a regular time for arising and retiring, and follow that schedule for three weeks. The third group of subjects will take two, brief scheduled naps each day and follow a regular schedule for arising and retiring. Control subjects will not alter their sleep patterns during the treatment period. Sleep diaries will be kept throughout the treatment period. At the end of two weeks, subjects will again complete the NSSC and undergo 24 hour ambulatory EEG monitoring. Since subjects will be taking their usual medications throughout the study, it will be possible to compare their daytime alertness on stimulant therapy alone with their daytime alertness when using a combined treatment approach (stimulants and scheduled sleep periods). These studies, when complete, should further define the sleep wake patterns in narcoleptics, give chronobiological insights into the temporal distribution of sleep periods in narcolepsy, and assess the effectiveness of scheduled sleep periods for controlling excessive daytime sleepiness experienced by patients with narcolepsy.